Just to recap, there are many solvents that will remove adhesives left from tape but depending on what the surface is made from, I'd normally recommend starting with the least aggressive and work my way up if necessary. Plain old mineral spirits (paint/varnish thinner) works well too, is slightly less volatile than some of the others mentioned and are less likely to damage the surface you are trying to clean. I've been caught with my pants down when it comes to Goo Gone, it dulled the surface of a glossy plastic door on my cloths dryer when I tried to remove some tape residue.... Mineral spirits didn't touch the surface at all, well at least not for the short period of time it took to get the rest of the tape off.

Regards

Christian